Seascape genetics sits at the intersection of population genetics and landscape ecology. This growing field, which addresses questions at shallower timescales than phylogeography, seeks to understand population genetic patterns in the context of ocean currents, habitat configuration and environmental characteristics.
Seascape genetic methods hold great promise for illuminating the basic metapopulation structure of marine species: a prerequisite to deeper understanding of marine ecology and evolution. However, progress on this problem has long been hindered by theoretical challenges raised by the typically large ranges and population sizes of marine species. My contributions to the field have been in pioneering an approach to marine population genetics that uses coalescent models in a model selection framework, which allows the evaluation of multiple alternative hypotheses of population structure (Crandall et al. 2012, 2014). My research shows that coalescent analysis of “panmictic” datasets (for which F-statistics are not significantly different from zero) will strongly reject the hypothesis of panmixia in favour of predictions from biophysical models of larval dispersal (Crandall et al. 2012). I am now in the process of working with Rob Toonen and Kim Selkoe to extend this method to 41 species sampled along the Hawaiian archipelago, and the lab is developing genomic markers and a sample collection to apply a similar approach along the coast of California.
Crandall ED, Treml EA, Barber PH. 2012. Coalescent and biophysical models of stepping-stone gene flow in neritid snails. Mol Ecol 21:5579–5598. doi: 10.1111/mec.12031
Crandall ED, Treml EA, Liggins L, Gleeson L, Yasuda N, Barber PH, Wörheide G, Riginos C. 2014. Return of the ghosts of dispersal past: historical spread and contemporary gene flow in the blue sea star Linckia laevigata. Bulletin of Marine Science 90:399–425. doi: 10.5343/bms.2013.1052
Riginos C, Crandall ED, Liggins L. 2016. Navigating the currents of seascape genomics: how spatial analyses can augment population genomic studies. Current Zoology 62:581–601.
Selkoe KA, D’Aloia CC, Crandall ED, Iacchei M, Liggins L, Puritz JB, Heyden von der S, Toonen RJ. 2016. A decade of seascape genetics: contributions to basic and applied marine connectivity. Mar. Ecol. Prog. Ser. 554:1–19.